Cooling device for printing machines



I Feb. 23, 1943. I H. G. MACDONALD COOLING DEVICE FOR PRINTING MACHINES I Filed Oct. 17, 1940 INVE I TOR Herb e?! G. )acd'anald I ALT; 1

N EYS Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE COOLING DEVICE FOR PRINTING MACHINES Herbert G. Macdonald, Oak Park, Ill., assignor to Charles Bruning Company, Inc., New York, N. Y., a corporation of New York Application October 17, 1940, Serial No. 361,545

6 Claims.

source. The cylinders so used are generally elongated in shape, i. e., of substantial length in relation to their cross-section, and the material from which they are formed, i. e., glass, is well known to be a poor conductor of heat. Accordingly, normal venting and cooling of the cylinder is negligible and, as a result,the heat produced by the centrally located light source rapidly raises the temperature of the glass cylinder to a point which is found to have undesirable eiiects upon the paper being printed.

Accordingly, it is an object oi. my invention to provide a device which is effective for controlling the temperature of the printing cylinder.

A further object of my invention is to provide a mechanism which is eiiective for controlling the temperature of the exterior surface of the printing roller.

Another object of my invention is to provide a venting mechanism which may be conveniently disposed within the printing cylinder so that a minimum amount of light is obstructed from the paper to be printed.

Another object of my invention is to provide a device for cooling the bands and the outer surface 01' the cylinder.

Other objects of my invention will be apparent from the following description of a preferred embodiment which is given in connection with the accompanying drawing, in which:

Figure l is a vertical sectional view of the venting mechanism as applied to a printing ma chine oi the glass cylinder type; and

Figure 2 is a diagrammatic drawing of the venting mechanism and the printing cylinder.

Referring to the drawing, a glass cylinder l is supported on a plurality of endless bands 2 which are mounted on a feed roll 3 and a plurality of elongated rolls I, 5, 6 and I. At least one of the rolls is provided with driving mechanism (not shown in the drawing) for imparting movement to the bands and to the cylinder.

the feed roll 3 and to be removed from between the'cylinder and bands adjacent the roll 4. A

light source 9 is disposed axially ofthe printing cylinder i. The above described mechanism is well known to the art and commonly has been used in photoprinting operations.

In accordance with the present invention, means are provided for cooling the exterior'and the interior of the cylinder l in order-to prevent damage to the paper being printed.

The exterior or the cylinder i may be reduced in temperature by means of the bands 2. Pre'ierably these bands 2 are made of dark-colored or black material so that they will absorb a greater proportion of the heat radiate'd uponthem through the cylinder l than would, the light-colored bands now commonly in use. In-

asmuch as the dark-colored or-black bands absorb and carry away a considerable amount of the total heat and do not reiie'ct'as much heat" to be absorbed by the cylinder l, the latter is maintained at an operating temperature insufllcient to damage the printing paper. means supplemental to the bands may be provided, if desired, although in practice the darkcolored or black bands in conjunction with'the venting and air-cooling meanshereinafter described ai'e suilicient to maintain the cylinder i at a satisfactory operating temperature.

The interior of the cylinder may be vented to reduce the internal temperature by means of an inlet duct l0 and an outlet duct l I which are adapted to maintain a circulation of cooling air within the cylinder. The ducts l0 and i I may be U-shaped in cross-section and preferably are sufilciently elongated to extend the entire length of the printing cylinder. Preferably the ducts in and H are disposed adjacent each other and adjacent the inner surface of the printing cylinder, between the feed roll 3 and roll I. By being disposed in this manner, the ducts l0 and ii do not intercept the passage of light from the source 9 to the paper to be printed. The inlet duct i0 is open at its ends to the atmosphere and is positioned so that the cooling air entering therethrough will be given .a downward direction by the rotation of the printing cylinder. The outlet duct H is faced in the opposite direction to the inlet duct so that a circulation of air around the interior of the cylinder is effected.

One end of the outlet duct II is connected by means of an intake tube l2 to a blower I3 which is driven by any suitable power source. such as The blower I3 is provided with a the motor l4.

Cooling I housing l5, which is connected to a baflle IS. The bafile I6 is disposed immediately below the endless bands 2 and the cylinder I and is adapted to disperse the air from the blower 13 across the entire length of the bands and cylinder and thereby to dissipate the heatirom and cool the bands 2.

It will thus be seen that I have provided an I effective mechanism for maintaining a positive flow of cooling air within the printing cylinderwhich reduces the temperaturesin the interior of the cylinder. In addition, the' air which is circulated through the cylinder is subsequently dispersed and directed against the endless bands to effect the cooling thereof. The. bands turn exert a cooling effect on the printing cylinder to provide an efiective cooling action throughout.

The circulation of air is. su ffic iently rapid to 'in-, sure that: the air withdrawn from -withinthe cylinder by-the blower is sufiicientlylow intern perature to cool the .bandsand cylinder. v

It will be apparentthat myinvention is sus ceptible to many variations by one slrilledin the 3. A cooling device for a printing machine having a glass cylinder, an endless band partially encircling said cylinder with a portion of its length while the remaining portion thereof is spaced from the cylinder, and a light source dis-.

posed within the cylinder and normally causing the cylinder and the band to" become heated;

said cooling device comprising a housing disposed adjacent the portion of the band spaced from said cylinder, and means to cause air to flow through the housing and against the band to dissip'ate'heat therefrom.

"4j.""A cooling-device for a printing machine having' a' cylinder to support material to be cylinder, and a light source to direct lightionto.

printed, an endless band partially encircling said cylinder with a portion of its length while the remaining portion thereof is spaced from the material supportedonsaid cylinder and/which normally causes the cylinderand the band to become heated; said cooling device comprising a housing disposed adjacent the portion of the art and all-such variations; are intendejdhto, be

included within the scope or, the following. claims. I

1. A cooling de v ice ,f or printing machine having a glass-cylinder and a light source disposed withinsaid cylinder normally causing the,

cylinder, to become heated; "said" cooling device comprising a plurality. of elongated members e f tendingwithin and lengthwiseof said cylinder and having a ;U shaped cross-section for circulating 2. {is cooling ;..device h having, j a glass cylinder,

bandfispaced fromsaid cylinder, andrm'eans .to

cause air to flow through the housing and against the band to dissipate heat therefrom;

5. A'Icooling device for a printing machine having .a-glass cylinder and a light source dis posed'within said cylinder normally causing the cylinderto become heated; said cooling device H comprising an elongated channelmember extending within and lengthwise of said cylinder and dir'ecting cooling air substantially tangen- I tially ofsaid cylinder, and'aseco'nd elongated I channel member adjacent to said first mentioned channel member for withdrawing the air from said cylinder after'it' has traversed the major portion [of the inner circumference of said comeih'eat'ed; said cooling,,,.devicef,comprisinga;

pair of elongated air conducting members ex tending within'andlengthwise of said. cylinder and in communication ,..jw ith.. t he.interior of the cylinder, along .the length thereof, oneof said members; being -.open to the, atmosphere ...and pumpi g m'eans communicatingwith the; other of said members,

, ing airljromth cylinder after it has traversed the major fportion lofthe circumference of said cylinder, and means for directing air against the bands-to aid in cooling said cylinder.,

cylinder;

6. A; cooling device for faprinting machine having agl'ass cylinder, a' plurality of' endle'ss ..heat absorbing lbands partially encircling said cylinder 'f and a light source'f disposed within the andnorm'allycausing the cylinder and i o become heated; said cooling devic v: I comprising'in'e'alns for conducting air to the cylinder and directing it substantially circumferen-- s (1 cylinder, means for withdraw- HERB'ERT G. MACDONALD. 

